Ibn `Abbas said: Duba`ah, daughter of al-Zubair bin `Abd al-Muttalib, came to the Messenger of Allah(SWAS) and said Messenger of Allah (SWAS) I want to perform Hajj; may I make a provision? He said Yes. She asked how should I say? He replied : Say “ Labbaik Allahumma Labbaik (I am at Thy service, Oh Allah, I am at Thy service). The place where I took off Ihram will be where Thou restrainest me.”
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا أَحْمَدُ بْنُ حَنْبَلٍ، حَدَّثَنَا عَبَّادُ بْنُ الْعَوَّامِ، عَنْ هِلاَلِ بْنِ خَبَّابٍ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، أَنَّ ضُبَاعَةَ بِنْتَ الزُّبَيْرِ بْنِ عَبْدِ الْمُطَّلِبِ، أَتَتْ رَسُولَ اللَّهِ صلى الله عليه وسلم فَقَالَتْ يَا رَسُولَ اللَّهِ إِنِّي أُرِيدُ الْحَجَّ أَأَشْتَرِطُ قَالَ " نَعَمْ " . قَالَتْ فَكَيْفَ أَقُولُ قَالَ " قُولِي لَبَّيْكَ اللَّهُمَّ لَبَّيْكَ وَمَحِلِّي مِنَ الأَرْضِ حَيْثُ حَبَسْتَنِي " .
sunnah.com